Introduction: In 2015, we used the Optovue Optical Coherence Tomograph (OCT) to demonstrate decreased cup-to-disc ratios (CDR) and increased retinal nerve fiber (RNFL) thickness in normal preschool children when compared to normal adults [1]. We undertook this validation using a similar instrument, the Heidelberg Retina Tomograph (HRT).

Methods: In a community-based, cross-sectional analysis, 77 four- to five-year- old healthy children were recruited from pediatric practices. No subject had any known ocular disorder. Their optic nerves were assessed concurrently using OCT and HRT. In addition to RNFL thickness and CDR, disc area (DA) and cup area (CA) measurements were compared.

Results: Measurements made on HRT showed an average DA of 1.96 mm2, CA of 0.37 mm2, CDR of 0.39, and RNFL of 184 um. On OCT, average DA was found to be 2.01 mm2, CA 0.36 mm2, CDR 0.38, and RNFL 104 um. A student t-test demonstrated a significant difference between the two imaging modalities only in RNFL measurements (p<0.00001).

Discussion: OCT and HRT agreed except for average RNFL thickness, previously demonstrated to be greater using HRT in adults [2].

Conclusion: Our results validate our previous conclusion that optic nerves of normal children are less cupped and their RNFL thicker than normal adults.